The RGBW liquid crystal panel (the liquid crystal panel in accordance with the red, green and blue and white four-color display technology) is by additional adding a W (white) pixel unit to the original RGB liquid crystal panel except the RGB three sub-pixel units, it makes the transmittance of the liquid crystal panel is greatly increased, thereby reducing the power consumption of the backlight, achieving the energy saving effect, and also enhance the contrast of the display image. However, since the introduction of W pixel unit into the RGBW liquid crystal panel, the apertures of the R, G, B three sub-pixel units in the RGBW liquid crystal panel is 75% of the conventional RGB liquid crystal panel, when displaying pure color image, the overall brightness of the RGBW panel is lower than the RGB panel, the display image is dimer.